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The kinetics of amide bond cleavage of isatin and N-methylisatin in the presence of ethanol was followed spectrophotometrically in the ranges of solvent composition (0-70%v/v) and temperature (40-60°C) using piperidine as a nucleophile. The reaction proceeds according to pseudo first-order kinetics. The rate of reaction strongly decreased with increasing organic solvent content. The thermodynamic activation parameters were calculated and discussed in terms of solvation. No linearity was observed between log (rate constant) and reciprocal dielectric constant for the solvent used, suggesting that there is selective solvation by the more polar water. The reactivity was analysed in the light of various simple and multiple regression equations using Kamlet–Taft solvatochromic parameters which were applied successfully to the mixed aqueous - ethanol mixtures. Finally, a mechanism for the ring opening is proposed

The kinetics of ring opening of azlactone in water -acetonitrile mixtures in the presence of morpholine have been studied under pseudo-first order condition in the temperature range 40 -60 C. Non-linear plots of log k obs with the reciprocal of relative permittivity of the solvent were obtained while linear plots of log k obs against the Y value were observed. The thermodynamic parameters DH 6 ¼ , DS 6 ¼ and DG 6 ¼ have been determined; DG 6 ¼ increases gradually as the mole fraction of the cosolvent increase, due to a complex quasi-mirror image compensation of DH 6 ¼ and DS 6 ¼ . The negative values of the entropy of activation and the non-linear relation of log k obs with the reciprocal of relative permittivity suggested selective solvation by the more highly polar water molecules. The isokinetic temperature obtained indicated that the reaction was enthalpy-controlled. The presence of an 207 electron-releasing or electron-withdrawing para-substituent in the benzylidene moiety affected the reaction rate, i.e. it being accelerated by p-Br but retarded by p-OMe substituents. Also the rate was decreased by increasing the content of organic cosolvent. The reactivity was analysed in the light of various simple and multiple regression equations using Kamlet -Taft solvatochromic parameters which were applied successfully in mixed aqueous -acetonitrile mixtures.

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This work was carried out to study the quality of water of Rosetta branch. Five sites were chosen for sampling during the period of January 2013 to December 2013. Physical parameters (Temperature, electrical conductivity (EC), turbidity and pH) and chemical parameters (concentration of Cl-, Ca+2, Mg+2, NH4+, SO4-2, NO2-, and some of trace metals, alkalinity, total hardness, Dissolved Oxygen(DO), Chemical Oxygen Demand(COD) and Biological Oxygen Demand(BOD) were discussed. These results were compared with the results of another study that were carried out at Rosita Branch at 2018. Statistical analysis of data was computed to show the correlation between some parameters through the whole sampling sites during the period of the study, using simple correlation coefficient.